Recently, the Ministry of Ecology and Environment and the State Administration of Market Supervision jointly issuedEmission Control Standard of Main Water Pollutants (Total Antimony, Total Molybdenum, etc.) in Danjiangkou Reservoir Area and Upstream (Trial) (GB 47946-2026)(hereinafter referred to as "Danjiangkou Standard"), this is the first basin-type discharge standard issued in the form of a national standard, and it is an important innovation to promote the prevention and control of water pollution in key river basins. it is of great significance to promote the construction of an ecological environment management system integrating upstream and downstream in important river basins. The relevant person in charge of the Department of Water Ecology and Environment of the Ministry of Ecology and Environment answered questions from reporters on the background, main considerations, and key content of the standard.

　　Q: What is the background of the Danjiangkou Standard?

　　Answer:Danjiangkou Reservoir is the water source of the middle route of the South-to-North Water transfer Project, which undertakes the task of supplying water to Beijing, Tianjin and cities in North China, taking into account agricultural and ecological water use, and plays an important role in the optimal allocation of national water resources and cross-basin water transfer strategy. The water quality of Danjiangkou reservoir area is generally good, and it maintains the state of medium nutrition all the year round, but there are some conventional pollutants in the basin that can not meet the standard stably, and the concentration of total molybdenum and total antimony is high in some periods. At present, the standards implemented by the main emission sources in the basin are not uniform, the total molybdenum and total antimony are not controlled enough, the non-point source emissions in the basin account for a relatively high proportion but lack of targeted control requirements, at the same time, the provincial standards are not uniform to form a joint force of control, which restricts the systematicness, integrity and synergy of basin governance.

　　In order to solve the above-mentioned problems, the "Danjiangkou Standard" was formulated in accordance with the policy of precise pollution control, scientific pollution control and pollution control according to law, and a river basin standard system of "upstream and downstream linkage, left and right bank co-governance, and a game of chess in the whole region" was constructed, so as to break the division of administrative divisions with a unified yardstick and promote the coordinated protection of upstream and downstream river basins.

　　Q: What are the main considerations for the development of the Danjiangkou Standard?

　　Answer:One is goal-oriented, overall consideration. In order to improve the quality of the water ecological environment of the basin and prevent the risk of the water ecological environment, the water ecological environment of the basin is screened and the control requirements are determined, and the water ecological environment problems of the basin are systematically solved. The second is to highlight the key points and implement precise policies. Focusing on the emission characteristics of the basin, in addition to strengthening the control of the antimony industry and the molybdenum industry, the differential emission control requirements or measures are put forward for all kinds of non-point source emission sources to improve the accuracy and effectiveness of basin management. Three is scientific control, effective and feasible. Carry out the investigation and analysis of the water environment and pollution sources in the basin, scientifically determine the emission limits by selecting applicable methods, and carry out technical and economic feasibility demonstrations to ensure the scientific application of standard limits.

　　Q: What are the main contents of Danjiangkou Standard?

　　Answer:The Danjiangkou Standard builds a comprehensive control system from point sources to non-point sources, from conventional pollutants to characteristic pollutants, and from traditional emission sources to new emission sources.

　　Regarding point source emission control: First, the discharge limits for certain urban centralized wastewater treatment facilities will be tightened. In view of the fact that the discharge limit implemented by individual urban sewage centralized treatment facilities with a scale ≥ 500m/d in the basin is relatively loose, which is not conducive to the improvement of water quality, it is clear that such centralized sewage treatment facilities will implement GB 18918 Class A standard from January 1, 2028. Second, refine the emission control requirements for the molybdenum and antimony industries. Combined with economic and technical feasibility, the total molybdenum and total antimony emission limits are reasonably determined, and the control of mining sewage discharge is strengthened, requiring the sewage units containing mining units to collect and treat the mine gushing water and meet the emission limits specified in the standard. Third, optimize the regulations for controlling indirect emissions. For alcohol manufacturing and other industries with good biodegradability of sewage, it is clear that indirect discharge limits can be negotiated on the premise of meeting the conditions; for other industries, the three kinds of destination of centralized treatment facilities for industrial sewage discharged into towns, single industry type and comprehensive type are distinguished, and the indirect discharge control requirements are clearly defined respectively. Among them, based on the nature of pollutants and the assessment of whether they can be effectively removed by the urban sewage treatment process, it is clear that the pollutants monitored by the sewage discharge outlets of workshops or production facilities, as well as formaldehyde, acrylonitrile, benzene, toluene, phenol, anilines and other pollutants should implement the direct discharge control requirements stipulated in the standards, reduce the discharge of such pollutants from the source, and effectively prevent the accumulated risks of the environment. Fourth, the regulatory requirements for centralized industrial wastewater treatment facilities are clarified. Distinguish between single-industry and comprehensive industrial sewage centralized treatment facilities, clarify the discharge standards or control requirements that should be implemented, and enhance the scientific nature of the control of industrial sewage centralized treatment facilities. Fifth, the comprehensive toxicity control indicators have been increased. Comprehensive toxicity (acute toxicity of zebrafish eggs) control requirements are put forward for comprehensive industrial sewage centralized treatment facilities, molybdenum industry, antimony industry and other non-ferrous metal industrial sewage discharge units to prevent water ecological environmental risks in the basin.

　　The Danjiangkou Standard also includes non-point source discharge into the control scope of the national water pollutant discharge standard for the first time, comprehensively covering all kinds of non-point sources such as polluted rainwater, aquaculture, livestock and poultry breeding, rural domestic sewage, etc., and includes new non-point sources such as rainwater and sewage combined overflow rapid treatment facilities and antimony-containing non-point source sewage treatment facilities, it realizes the double expansion from "only point source" to "full coverage of point and surface", from "traditional non-point source" to "new non-point source. For the treatment of antimony-containing non-point source sewage, the innovation put forward the "zoning differential bottom limit" model, giving the local according to the distance between the mining area and the water source area, river water and other factors, combined with the section of the total antimony control target independent determination of the flexible space. This model not only respects regional differences, but also keeps the safety bottom line, providing a replicable method paradigm for non-point source control in other similar regions of the country.

　　Q: What are the benefits of the implementation of the Danjiangkou Standard?

　　Answer:Danjiangkou Standard effectively promotes the emission reduction of conventional pollutants, total molybdenum and total antimony in the basin by implementing classified and accurate control of point sources and non-point sources. Increase comprehensive toxicity control requirements for comprehensive industrial sewage centralized treatment facilities and strengthen environmental risk prevention; For those who discharge sewage into urban sewage centralized treatment facilities, it is clear that formaldehyde, acrylonitrile, benzene and other pollutants will be uniformly discharged into direct discharge standards, prevention of environmental cumulative risks caused by the difficulty of effective treatment of characteristic pollutants. In addition, the standard guides local differentiation to determine the emission control requirements of antimony-containing sewage treatment facilities, taking into account the cost of treatment and the effectiveness of pollution control, and steadily improving the water quality of the basin. Therefore, the implementation of the standard yields significant environmental, economic, and social benefits.

　　Q: How to promote the implementation of standards?

　　Answer:First, effectively carry out the dissemination and implementation of standards. Effectively interpret standards through multiple channels and proactively address key issues of public concern. Carry out training for local ecological and environmental authorities and related enterprises to solve problems in the implementation of standards in a timely manner. Second, we will strictly enforce the law and strengthen oversight. In accordance with the provisions of the standards, the ecological and environmental departments shall strengthen law enforcement, investigate and deal with environmental violations in accordance with the law, and promote the continuous improvement of the water environment quality of the river basin. Third, strengthen technical assistance. Guide local governments to promote the orderly upgrading of pollution control facilities by relevant enterprises, scientifically determine the total antimony emission limit of collection and treatment facilities for antimony-containing non-point source sewage, comprehensively improve the efficiency of pollution prevention and treatment, ensure discharge standards, and promote high-level protection and high-quality development of river basins.